UHF Pirates – 250 MHz SATCOM Monitoring

UHF SATCOM refers to satellite repeaters that operate between 240 MHz and 270 MHz. To receive SATCOM, you need a receiver that can tune the frequency range in narrow FM (most modern scanners can do this). You also need an outside antenna, and possibly a LNA preamp.

The satellites in question are operated by the US military. They are essentially repeaters in geostationary orbit. Because they are open (no access control) they are often used by third parties, most often by people in Brazil. It is very common to hear Portuguese transmissions. One listener, who spent several years living in Brazil, described it as

While you can start with a basic outdoor scanner antenna, such as a discone antenna or other scanner antenna, many serious listeners eventually build a directional antenna, such as a helical. I will have construction information about one that I built in a future article.

Next, since the signal levels are often very weak, the use of a LNA preamp is highly recommended. I built one of the Down East Microwave Inc. GaAs pHEMT pre amp kits, and find that it really helps a lot.

For the past two days, I’ve been hearing the pirates on 252.150 MHz, after making my own off-center dipole antenna from copper pipe! One side is 4 feet, and the other side is 18 inches. I have it up on my wall about 6 feet, and it receives them great at times, yet fades in and out at other times. This is my first reception of Brazilian pirates using these satellites. My radio is a Yupiteru MVT-7100. Great article!